Synthetic solvent still

ABSTRACT

An Apparatus for the continuous distillation and recovery of cleaning fluid from a source of contaminated fluid has a chamber, a still within said chamber and a means to prevent &#39;&#39;&#39;&#39;boil over&#39;&#39;&#39;&#39; of the apparatus.

I Umted States Patent 1 '11 11 3,766,017 Moss Oct. 16, 1973 SYNTHETICSOLVENT STILL 1,257,854 2/1918 Han-is 159/31 x 2,718,215 9/1955 Bossertet a1. 159/31 X [75] Invenmn Harry cynwyd 3,057,786 10/1962 Waddilll203/20 731 Assignees; Helen S. M Harry Moss 3,711,070 1/ 1973 Khokhlouet a1. 159/D1G. 4

Cynwyd, Pa. part interest to each [22] Filed: 1971 PrimaryExaminer-Norman Yudkoff [21] Appl. No.: 195,735 Assistant Examiner-J.Sofer AttorneyFrank J. Benasutti v [52] US. Cl 202/187, 202/197, 203/20,159/23, 159/28 [51] Int. C1. B011d 3/00, F28b BOlb 1/02,

BOld 19/02, BOld l/00, BOld 19/00 57 T A [58] Field of Search 202/170,186, 187,

202/189, 197; 203/20; 159/1 A, DIG. 4, 31, v

43, 16 A, 16 S, 27 D, 1 C 23, 28 R, 13 A; An Apparatus for thecontinuous distlllation and re- 252/359 E 361 covery of cleaning fluidfrom a source of contami nated fluid has a chamber, a still within saidchamber [56] References Cited and a means to prevent boil over" of theapparatus.

UNITED STATES PATENTS 863,031 8/1907 Lehnert 202/264 2 Claims, 2 DrawingFigures 20 CONTAMINATED SOLVENT IN coouuc WATER V g/ j STEAM VAPOR |NCOOLING 34 0 II J WATER l 1 fi 24 FOAM: i I E v i I EVAPORATOR l 1 1TAN1 II 10 INDIRECT 22 i 1 FONDEYNSER CHAMBER I I I J23 I 1 I I! u I M2e 551 3 4 1 RESIDUE 27 DRAIN r u 28 l l BOCONDENSATE 4/ COLLECTOR AND4- WATER SEPARATOR Patented Oct. 16, 1973 CONTAMINATED SOLVENT COOLINGINDIRECT 22 CONDENSE R 2 SheetsSheet 1 COOLING WATER 25 2| ST AM I 32VAPOR ,E

I I I j I .I I 7 FOAM| I I I I I I I: I I '-EVAPORATOR I II I TANK I II1 I I CHAMBER M I I: J23

| I I I I I E L) I I I I I I l I sTEAIvI 26 OUT RESIDUE DRAIN 28 I//3OCONDENSATE 4/ COLLECTOR AND wATER SEPARATOR Patented Oct. 16, 19733,766,017

2 Sheets-Sheet 2 CONTAMINATED I SOLVENT IN L I 44 46 h -STEAM IN fsoSYNTHETII'C SOLVENT STllLlL BACKGROUND OF THE INVENTION This inventionrelates to distillation equipment, and more particularly, to a still andrelated equipment for use in the dry cleaning industry in distillingsynthetic solvent such as perchloroethylene.

In the prior art a wide variety of stills exist for this purpose. In onepopular piece of apparatus a large tank is provided with a steam heatedbase. Dirty solvent is pumped into the steam heated tank which normallycontains an aitator to keep the solvent moving as the sludge filters outand the solvent boils and is evaporated. The tank is generally vented sothat some of the solvent vapors escape into the atmosphere causing airpollution. To my knowledge stills on the market in actual use are ratherlow capacity, low efficiency devices producing a low quality output.

SUMMARY OF THE INVENTION It is my desire to provide by my invention ahigh output, high efficiency still which will produce a high qualityproduct in a minimum of space without polluting the air.

My invention comprises an apparatus having a still of uniqueconstruction disposed in a recovery tank and having means for inhibitingfoaming boil over during the process of distillation. Also provided iscondensing and liquid solvent recovery means.

Accordingly its an object of my invention to provide an apparatus of thetype described for purifying cleaning fluid and this and other objectsof'my invention will become apparent from the following description withreference to the accompanying drawings.

BRTEE DESCRIPTION OF THE DRAWINGS FIG. l is an over all schematicelevation of an apparatus in accordance with my invention; and

HO. 2 is a greatly enlarged vertical section of a portion of theapparatus shown in FIG. 1.

DESCRIPTION OP THE PREFERRED EMBODIIMENTS Although specific forms of theinvention have been selected for illustration in the drawings, and thefollowing description is drawn in specific terms for the purpose ofdescribing these forms of the invention, this description is notintended to limit the scope of the invention which is defined in theappended claims.

The overall apparatus as shown in FIG. ll comprises a largesubstantially cylindrical tank T forming a chamber in which is mountedthe basic evaporator means in accordance with my invention, designatedgenerally 12. The cylindrical tank has a bottom plate M with a drain it(as indicated) for manual drainage of residue from the tank. The upperend of the tank has a plate 113 welded or otherwise suitably affixed tothe side wall. The vapor collection means comprises an open tube 2llfixedly mounted in the plate 113 to receive the gaseous mixtureevaporating from the evaporator (as will be described more fullyhereinafter). This gaseous mixture passes through the tubing designatedgenerally and the side mounted, indirect condensers 22 and 23. Thesehave not been shown in greater detail for purposes of the presentapplication, since condensers are well known in the distillation art.The condensers have suitable piping (not shown) connected at thefittings generally designated 2d, 25, 26 and 27 for the passage ofcooling water therethrough to condense the gaseous mixture into a liquidform which then flows through the horizontal pipe 28 at the bottom ofthe apparatus. The liquid is then collected, and the water separated outas is well known in the art, in a collection means designated generally3U from which it is then reintroduced through the cleaning plant.

As shown in both FIGS. 11 and 2 the dirty or contaminated liquidcleaning solvent is fed through a metering device (not shown) into thestill apparatus at the top through a relatively small pipe 32 (on theorder of 54:; inch in diameter). This pipe is retained in a flat plate34 which is mounted above the chimney shaped portion, evaporator 12, andextends beyond the edges thereof. The solvent discharges from the lowerend of the pipe 32 onto the base 36.

The means for supplying heat to evaporate this solvent comprises a steamjacket which I shall now describe in greater detail. The jacketcomprises two cylindrical concentrically, vertically mounted tubes. Theinner tube 38 is welded at one end to the base 36 as shown. The outertube 40 is somewhat shorter and is welded to upper plate 42. The twotubes are connected together at the top by an annular member M which iswelded to each of the tubes to provide a seal. This annular mmbersupports the legs M5 which in turn support the plate 34 above and spacedfrom the open end d3 of the chimney shaped longitudinally extendingcontainer portion of the evaporator 112.

The upper plate 42 and base 36 are connected by an annular side wall andare suitably welded so as to provide a substantially sealed container.Of course, the total steam jacket is opened at both ends to permit steamto enter through the pipe 32 and exit through the pipe 54 in the base36. The base is supported by a plurality of legs 56, so that it standsabove the base M of the tank 10 (shown in phantom lines in FIG. 2).

METHOD OF OPERATION In the operation of this apparatus, it is desirableto preheat the steam jacket prior to feeding the solvent into the still.The steam is turned on first and the appa ratus brought up to adesirable temperature depending on the quantity of solvent involved andthe rate at which evaporation is to take place. These parameters canreadily be determined by one skilled in the art. The cooling watershould be turned on so that the condensers are functioning when vapor isintroduced into them. Next the liquid solvent is fed in through the pipe32 and allowed to drop onto the base 36 in the heated jacket. Note thatthe solvent is preheated in passing through the pipe 32. The solventbegins to evaporate and vapor, liquid and foam pass upwardly through thepipe 33, out the top 48, contact the plate 3d and then the vapors riseinto the pipe 211 while the liquid and foam pass down along the outsideof the pipe MD. The vapors pass into the condensers and are condensedand collected as a liquid.

During'this process the solvent foams. The foam is beneficial to acertain extent in that it carries with it impurities. However, prior artdevices were subject to boil over due to uncontrolled foaming; and thisresulted in malfunctioning of the prior art apparatus. in the presentinvention adverse foaming action is prevented by the plate 34 spacedabove the opening 4m in r the chimney shaped portion of the evaporator112. As

the foam works its way up the pipe 38 it is inhibited from proceedingmuch beyond the open end thereof by the plate 34 and instead drips fromthe under side of the plate and runs down the outer sides of the outertube 40 and onto the upper hot plate 42. in doing so, condensed orotherwise unevaporated solvent in the foam is caused to evaporate,thereby increasing the efficiency of the still. Thus, the percentage ofsolvent removed from the impure liquid is increased, while substantiallyonly the impurities run down the side of the tube and on to the upperplate 42 and ultimately onto the bottom of the tank 14 and out the drain16 from where the residue can be removed manually.

I have observed the operation of an apparatus in accordance with myinvention which was installed on a test basis and have found that threetimes the quantity of liquid could be processed in the same time asprior art methods at a greatly increased quality even though the spacenecessary for processing was approximately only one-half that previouslyrequired.

It will be understood that various changes in the details, materials andarrangement of parts which have been described and illustrated in orderto explain the nature of this invention, may be made by those skilled inthe art within the principle and scope of the invention as expressed inthe appended claims. In particular, more than one chimney shaped portioncould be used with a common steam jacket base and suitable piping. Alsothe outer tank could be of a prior art type and have, for example, abuilt-in steam heated base.

While specific dimensions have not been given, the drawings are inproportion to the preferred embodiment.

It will be further understood that the Abstract of the Disclosure setforth above is intended to provide a nonlegal technical statement of thecontents of the disclosure in compliance with the Rules of Practice ofthe United States Patent Office, and is not intended to limit the scopeof the invention described and claimed herein.

What is claimed is:

l. A distilling apparatus, comprising:

a. a chamber;

b. an evaporator means within said chamber for receiving and evaporatingsolvent from a solventcontaining liquid and, in operation, causing saidsolvent to evaporate, leaving a foaming liquid residue; said evaporatormeans comprising a container extending longitudinally in the verticaldirection, said container being open at its upper end to permit exitingof said foaming liquid and closed at its lower end and being embraced bya steam jacket;

c. means for introducing a solvent-containing liquid into said containercomprising a conduit suspended vertically in said container, saidconduit terminating in an open end spaced from the closed end of thecontainer so that fluid passing through said conduit will fall bygravity to said closed end;

d. vapor collection means opening into said chamber for collecting thesolvent vapor produced; and

e. means juxtaposed with said evaporator means to prevent said foamingliquid from entering said vapor collection means.

2. The invention of claim 1 wherein said steam jacket comprises asubstantially cylindrical body rising from a base which extends radiallyoutwardly so as to be contacted by the foaming liquid which overflowssaid evaporator means and falls thereon by gravity.

1. A distilling apparatus, comprising: a. a chamber; b. an evaporatormeans within said chamber for receiving and evaporating solvent from asolvent-containing liquid and, in operation, causing said solvent toevaporate, leaving a foaming liquid residue; said evaporator meanscomprising a container extending longitudinally in the verticaldirection, said container being open at its upper end to permit exitingof said foaming liquid and closed at its lower end and being embraced bya steam jacket; c. means for introducing a solvent-containing liquidinto said container comprising a conduit suspended vertically in saidcontainer, said conduit terminating in an open end spaced from theclosed end of the container so that fluid passing through said conduitwill fall by gravity to said closed end; d. vapor collection meansopening into said chamber for collecting the solvent vapor produced; ande. means juxtaposed with said evaporator means to prevent said foamingliquid from entering said vapor collection means.
 2. The invention ofclaim 1 wherein said steam jacket comprises a substantially cylindricalbody rising from a base which extends radially outwardly so as to becontacted by the foaming liquid which overflows said evaporator meansand falls thereon by gravity.